{
 "public_id": "AIR-2025-0076",
 "incident_id": "2025-08-cloudflare-perplexity-stealth-crawling",
 "date_disclosed": "2025-08-04",
 "date_occurred": null,
 "title": "Cloudflare: Perplexity used undeclared stealth crawlers impersonating Chrome to evade robots.txt and site blocks",
 "class": "in_the_wild",
 "attack_surface": "browser_agent",
 "initial_vector": "agent_identity_spoofing",
 "agent_capability_abused": [
  "automated_web_fetching",
  "user_agent_spoofing",
  "ip_asn_rotation"
 ],
 "target_product": "Perplexity crawlers / Perplexity-User agent fetches",
 "target_vendor": "Perplexity",
 "autonomy_level": "fully_autonomous",
 "impact_realized": true,
 "impact_type": [
  "policy_violation",
  "unauthorized_access",
  "reputational_harm"
 ],
 "blast_radius": "tens of thousands of domains, 3-6M stealth requests per day",
 "cve": [],
 "taxonomy": {
  "owasp_asi": [
   "ASI03"
  ],
  "mitre_atlas": [],
  "labels": [
   "agent_detection_bypass",
   "user_agent_spoofing",
   "robots_txt_evasion",
   "verified_bot_delisting",
   "disputed"
  ]
 },
 "defense_present": "robots.txt, WAF blocks, Cloudflare verified-bot program",
 "defense_bypassed": true,
 "fix_shipped": "Cloudflare de-listed Perplexity as a verified bot and shipped detection heuristics in managed rules",
 "primary_sources": [
  "https://blog.cloudflare.com/perplexity-is-using-stealth-undeclared-crawlers-to-evade-website-no-crawl-directives/"
 ],
 "verified_quote": "Perplexity uses not only their declared user-agent, but also a generic browser intended to impersonate Google Chrome on macOS when their declared crawler was blocked.",
 "confidence": "high",
 "notes": "Real-world, not a PoC: site operators' stated no-crawl policies were actually violated at scale, and Cloudflare took enforcement action. Included because it is the load-bearing precedent for agent-detection bypass by a browser-agent vendor. Perplexity publicly disputed Cloudflare's characterization, arguing user-triggered fetches are not crawling; that dispute is unresolved. Compare with the later Amazon v. Perplexity litigation over Comet shopping agents.",
 "risk_category": "security_fraud",
 "risk_secondary": [
  "product_misuse"
 ],
 "risk_subcategory": "Unauthorized Access & Account Takeover",
 "risk_sub_secondary": [],
 "ai_entity": "generative",
 "agency": "agent_acted",
 "agency_debatable": false,
 "agency_reason": "the crawlers fetched pages in violation of stated no-crawl policies",
 "vector_family": "other",
 "vector_detail": "agent_identity_spoofing",
 "guardrail_kind": [
  "unknown"
 ],
 "guardrail_outcome": "silent",
 "xrefs": {
  "aiid": [],
  "atlas": [],
  "cve": [],
  "ghsa": []
 },
 "primary_asi": "ASI03",
 "agent_framework": "unknown",
 "model_provider": "unknown",
 "model_name": "",
 "detection_mechanism": "unknown",
 "tool_access": "unknown",
 "financial_loss_band": "unknown",
 "eai_category": "privilege_escalation",
 "eai_domain": "access_control_and_permissions",
 "eai_secondary": [
  "human_manipulation"
 ],
 "eai_reason": "subcategory: Unauthorized Access & Account Takeover",
 "asi_curated": [],
 "asi_scope": "in_scope",
 "asi_provenance": "rule",
 "asi_reason": "ASI03 (signal=identity)",
 "submitted_by": "EAI Internal"
}